This timeline details pandemics through history

A pandemic is defined as a disease that spreads across a wide geographical area. Pandemics are generally caused by a new virus, or by a strain of an existing virus that spreads rapidly. They may also be caused by bacteria, though this is rarer nowadays unless it is resistant to antibiotics.

This timeline is a chronology of the spread of the Black Death that reached Europe in the mid 14th century killing around 50 million people – possibly as many as two thirds of the population.

It was originally thought that the disease was spread by black rats, but due to the rate of spread and the lack of evidence of large numbers of rat corpses (Bubonic plague kills rats), it is now thought that the bacillus that caused the disease was airborne; spread by the victims themselves.

This timeline details the main events covered in the first 40 years of the twentieth century, including World War One and the Inter War Years, and is linked to the GCSE topic Peace and War: International Relations 1900 – 1939

A Timeline of Taoiseach (Prime Minister) of Ireland from 1919 to present day

In January 1919, members of Sinn Féin refused to take their seats in Westminster. Instead they formed their own parliament Dáil Éireann and pushed for self-governance. The Anglo-Irish Treaty of December 1921 granted self-government to 26 counties of Ireland, to be named the Irish Free State, while the other 6 counties in the north remained a part of the United Kingdom. The treaty included a clause which stated that the government of Ireland had to swear allegiance to the British monarch. Members of Sinn Féin, including leader Éamon de Valera refused to take this oath and did not take their seats in government. In 1931 the Statute of Westminster passed full authority to the Irish Free State. Éamon de Valera founded a new party Fianna Fáil and when he was elected he abolished the Oath of Allegiance. In 1937 de Valera changed the constitution and the Irish Free State became Ireland. In 1949 Ireland became the Republic of Ireland.